Little B when he gets yelled at for doing something wrong

Sometimes I think that Little B must be the sweetest toddler on the planet.  When I tell him no and he knows that I am being serious he immediately puts his head down and comes to me for a hug.  Then I feel like a terrible witch for yelling at such a sweet little boy.  But then five minutes later he goes right back to doing the exact thing I told him not to do and then I remember why I yelled.